We have established a syngeneic mouse brain tumor model in which tumor growth or disappearance can be easily monitored using bioluminescence imaging. We have successfully treated tumors with microglia obtained from neonatal animals as proof of principle that a microglial treatment strategy may be effective. On average, treated groups achieve a long term survival rate of 60%-70% whereas control animals routinely achieve a 0% long term survival rate. We have created iPS cell lines from mice syngeneic to those implanted with tumors and have fully characterized their multipotency using teratoma formation and blastocyst injections. We have developed a protocol for differentiating the iPS cells into microglia and are in the process of characterizing these cells to confirm their microglial identity. Methods that are effective in the treatment of our mouse tumors will be translated to the human setting.